1. Try putting her in a sit/stay, and make her stay, and gradually get farther away from her. When she has mastered that, put a treat 6' from her on the floor, and do a sit/stay until you release her to get the treat. During both of these things, have your mom/dad help by "distracting" her by dropping something, making a noise, a squeaky toy, etc. and don't let Layla get up for anything other than your release word. Emma can do this with some amount of distraction, but I'm not sure about the metal bowl. I think you'll need to work up to that!
Don't know how to help you with #2!
3. Maybe check in your area and see if there is a nursing home/physical rehab center that allows pets. You could start just making rounds with Layla there to chat with the people, or go in and play games/do puzzles in the lounges with the people there. She would get used to the different sights/smells/sounds and of course the wheelchairs. You might hold Layla or put her in a bag at first. Of course, you couldn't really let her interact too much with the residents since she wouldn't be "certified", but if you told them you were practicing for her test, they might let you explore and help out with what you can!
My grandmother was in a physical rehab center for 3 weeks after knee replacement surgery, and they had a resident therapy dog that came around with a handler and she was really nice, calm, and affectionate. Her name was Jasmine (after the Disney princess) and she was a smaller Corgi. I think she was a nice surprise for many of the people, and she was a really happy dog!